"Philip:  I have finally achieved auto tune.  As James says below, you must NOT be moving the sticks when you enter auto tune.  In my case, my trims were not correct.  After I ran auto trim, I could then do auto tune.  As far as I know, there is no…"

"Wind was up even before daybreak, so no tests yet.
James: You said " Check  RCX_TRIM parameters and compare them to exactly what the APM is seeing (I graphed the live values in MP). Either trim your Tx or adjust the parameters".  
How exactly did…"

"I have same problem.  Will try James's solution tomorrow and see if it works...
Stay tuned..."

"Thanks, MikeRover.
1. My rover is based on a rock crawler with 4WS and FWD (I removed the RWD motor).  Max speed is ~ 1.8 M/s on grass and 2.2 on hard surface.  This is OK for me.  I am more interested in pursuing smoothness and precision rather…"

"Thanks, TCIII, that seems to work.  Any value below 13 does not work on the test stand. This probably depends on ESC used.
I suggest the default be set to 30 to keep other newbies from suffering the same mistake.
Now I can do some tuning!
Thanks…"

"Follow up:  Went to larger field and got same results as smaller field.  I still have to use throttle in Auto mode.
I did confirm that RTL works as expected but once again had to use manual throttle in RTL."

"Thank you MikeRover for your help.  
Note that I am not deliberately trying to Kickstart and my current Kickstart param = zero, therefore I am looking for normal throttle response to auto mode.
1. Current values: Cruise speed = 0.4, Cruise throttle…"

"DUH! pilot error again.  
APM output pins reversed, probably related to previous brain fart.

Will try your suggestions. Thanks for your help."

"Thanks TCIII,
param file attached as debug.param
distance from home & rover to WP 1 is 288M 
telem enabled, hdop 4, sats 7-8

compass current heading red line is accurate, gold line is accurate, black line jumps all over, green line bisects red and…"

"My code is crude but effective but I do not want to put it into public distribution.  However, if you want to play with it, PM me with your email address and I will send it to you "as is, without warranty, etc," ;-)"

"Unfortunately NO.  As far as I know, the pinouts are different between various flavors of Arduino.
If you are thinking of implementing APM code on a UNO, I do not think it will work due to memory limitations.
I am no Arduino expert though, so feel…"

"Thanks GregM.  Problem went away in a weird way.  Shut down computer last night with nothing working, started computer in morning and USB works.  I did absolutely nothing to change the situation.  "